Degenerative-dystrophic spine diseases and back pain

Despite the etiological differences in the genesis of degenerative (involutional, associated with aging) and dystrophic (metabolic) lesions of the musculoskeletal system, the clinical and radiological picture of diseases has not yet clearly identified the features inherent in each of these processes.

The historically established phrase "degenerative-dystrophic lesions" is widely used in medical literature, although for most diseases considered in this section the term "dystrophic" is more justified. At the same time, depending on the severity of metabolic disorders and their prevalence, clinical symptoms and radiographic changes in the musculoskeletal system may have different expression.

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Scheuermann's disease

In modern vertebrology, Scheuermann's disease (juvenile kyphosis) is considered a particular form of Scheuermann's dysplasia (juvenile osteochondrosis), the severity of the manifestations of which is very individual and depends on hereditary factors, the patient's age and the level of damage (thoracic or lumbar region). On the basis of Scheuermann's dysplasia, degenerative osteochondrosis and back pain, characteristic of older patients, may develop. The dynamics of radiological changes in this pathology allows us to introduce the concept of the Scheuermann's dysplasia scale, which can be designated by a diagram in which the horizontal axis corresponds to the increasing age of patients.

Typical radiographic signs of Scheuermann's dysplasia are: widespread wedge-shaped vertebral bodies, the presence of Schmorl's nodes, decreased height of intervertebral discs and gentle kyphosis (typical for the thoracic spine). It is important to emphasize that the simultaneous presence of all of these signs is not at all necessary for making a diagnosis. The maximum severity of Scheuermann's dysplasia corresponds to the radiographic Sorenson criterion, typical for the thoracic spine and including two signs: wedge-shaped vertebral bodies exceeding 5° and damage to at least three adjacent vertebrae.

Two independent diseases - juvenile kyphosis of Guntz and fixed round back of Lindemann are accompanied by a gentle kyphosis and back pain, i.e. clinical manifestations that most closely resemble juvenile kyphosis of Scheuermann. However, typical radiographic signs allow us to differentiate these conditions.

Clinical and radiological signs of juvenile kyphosis of Guntsch and fixed round back of Lindemash

	Clinical signs	Radiographic signs
Juvenile kyphosis of Guntz	Slouching or rounded back, Pain syndrome - in 50% of patients.	Wedge-shaped discs, the base of the wedge facing backwards Correct rectangular shape of the vertebral bodies Absence of Schmorl's nodes and endplate defects
Lindemann Fixed Round Back	Pronounced stoop. Stiffness of the spine in the deformation zone.	Wedge-shaped vertebral bodies Wedge-shaped discs, the base of the wedge facing forward Absence of Schmorl's nodes and endplate defects.

Spondylosis

Spondylosis, or limited calcification of the anterior longitudinal ligament, is traditionally considered in the literature as a variant of degenerative-dystrophic damage to the spine, although there is also an opinion about the traumatic nature of this pathology.

The distinctive clinical and radiological signs of spondylosis are:

• absence of back pain (in the overwhelming majority of observations) in the presence of pronounced radiological signs of local ossification of the anterior longitudinal ligament;
• damage to 1-2, less often - 3 segments, more often - in the lumbar region;
• absence of reduction in the height of the intervertebral discs. The presence of a reduction in the height of the disc indicates a combination of chondrosis and spondylosis;
• the formation of osteophytes does not have strict symmetry, and they themselves are distinguished by an irregular shape and fringing;
• osteophytes have a typical direction and localization: they usually begin outside the epiphyseal plate zone from the level of attachment of the anterior longitudinal ligament to the vertebral bodies, and are directed upward and downward in relation to the intervertebral disc, bending around it. Less often, ossification of the anterior longitudinal ligament detached as a result of injury begins at the level of the middle of the disc, or "counter" ossification is observed, originating from the vertebral bodies located cranially and caudally in relation to the adjacent disc (the "parrot's beak" symptom), up to complete fusion of the apophyses. In osteochondrosis, the localization and direction of Junghans's spines have a horizontal direction. The appearance of beak-shaped bone growths is possible not only with spondylosis, but also with Forestier's disease (syn. fixing hyperostosis, fixing ligamentosis).

Differential diagnostic features of spondylosis and Forestier's disease

Sign	Spondylosis	Forestier's disease
Localization of the beginning of the process	Most often the lumbar vertebrae	Usually the central thoracic segments (usually on the right). Less often the lumbar segments (usually on the left).
Prevalence of the process	1-2, rarely 3 segments	A large number of segments, often entire sections of the spine are affected
Disk condition	Not changed	Not changed
Joints of the axial skeleton	Not affected	Not affected
History of trauma	Available	No
Rigidity of the spine	In a limited area	Common

Spondyloarthrosis

Spondyloarthrosis is a degenerative lesion of the articular cartilage of the facet joints, accompanied by stretching and pinching of their capsule, dystrophy and subsequent ossification of the ligamentous apparatus of the spine. Symptoms of spondyloarthrosis include back pain, often of a somitic, less often of a radicular nature; radiological - subchondral sclerosis of the articular surfaces, narrowing of the joint space up to its complete disappearance, bone growths in the joint area and deformations of the articular processes.

Both clinical examination and functional X-rays of the spine reveal a limitation of the range of motion caused by the block of the spinal motion segment. Being its integral part, the facet joint is subject to functional overload in any pathology of the spinal motion segment. That is why the dystrophic process in the disc usually occurs with spondyloarthrosis. In the absence of dystrophic changes in the discs, isolated damage to one or more joints can be caused by deformations of the spine in any plane, trauma or dysplasia that disrupt the normal function of the joint. The formation of spondyloarthrosis can be facilitated by:

• tropism anomalies - spatial orientation of the facet joints. Asymmetry of paired facet joints, in which arthrosis does not develop, usually does not exceed 20°;
• anomalies in the size and structure of the facet joints: different sizes, wedge-shaped and saddle-shaped joints, aplasia of the articular process, additional ossification nuclei;
• the presence of transitional vertebrae and their anomalies;
• disorders of fusion of vertebral bodies and arches;
• disturbances in the formation of the vertebral arches.